afriso Eurovac NV Notice Technique page 68

4.4 Function
Via the suction line, the vacuum pump installed in the product generates a
vacuum in the interstitial space of the tank (low vacuum range). The pressure
switch measures the pressure in the interstitial space via the measuring line
and keeps it at a constant level together with the vacuum pump.
If a leak occurs in the inner or outer wall of the tank (tank wall or the leak pro-
tection lining) above the level of the stored liquid or the ground water, and if
this leak is greater than the suction capacity of the vacuum pump, the vacuum
will drop. When the alarm threshold for the switching point is reached, the red
LED lights permanently and the audible alarm is activated. The relay is ener-
gised. The audible alarm can be switched off by pressing the Acknowledge
button.
If liquid from the outside or the inside gets into the interstitial space and if this
liquid is sucked in, the liquid barrier shuts off the suction line. This immedi-
ately triggers an alarm.
4.5 Relay output
The product features a voltage-free changeover contact. If no alarm is pres-
ent, the relay is de-energised. In case of an alarm, the relay is energised and
switches the changeover contact.
The product can be operated with or without additional external equipment,
for example:
• Visual and audible alarm units
• Remote alarm equipment
• Building control systems
4.5.1 Products with EnOcean® wireless module
In the case of an alarm, the wireless module transmits the alarm message
via EnOcean® wireless technology in addition to the visual and audible
signals.
Product description
Eurovac NV
EN
14